linux-kernel - Re: [PATCH 1/2] rtc-rv8803: fix writing back ctrl in flag register

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Message-ID: <YYiWq564QzQgTsqV@atmark-techno.com>
Date:   Mon, 8 Nov 2021 12:16:59 +0900
From:   Dominique Martinet <dominique.martinet@...ark-techno.com>
To:     Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Alessandro Zummo <a.zummo@...ertech.it>
Cc:     linux-rtc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] rtc-rv8803: fix writing back ctrl in flag register

Hi Alexandre, Alessandro,

the other patch was proved to be unneeded, but this one is still a valid
fix as far as I can understand the code (reusing RV8803_CTRL value to
write into RV8803_FLAG does not look correct)

(I'm also convinced either mostly work because the original values are
usually close enough, but that's not a reason to keep using the wrong
one)


Would you have time to take a look?


Thanks!

Dominique Martinet wrote on Mon, Nov 01, 2021 at 10:33:59AM +0900:
> ctrl is set from read_regs(..FLAG, 2, ctrl), so ctrl[0] is FLAG
> and ctrl[1] is the CTRL register.
> Use ctrl[0] to write back to the FLAG register as appropriate.
> 
> Signed-off-by: Dominique Martinet <dominique.martinet@...ark-techno.com>
> ---
>  drivers/rtc/rtc-rv8803.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/rtc/rtc-rv8803.c b/drivers/rtc/rtc-rv8803.c
> index 72adef5a5ebe..0d5ed38bf60c 100644
> --- a/drivers/rtc/rtc-rv8803.c
> +++ b/drivers/rtc/rtc-rv8803.c
> @@ -340,8 +340,8 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
>  		}
>  	}
>  
> -	ctrl[1] &= ~RV8803_FLAG_AF;
> -	err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[1]);
> +	ctrl[0] &= ~RV8803_FLAG_AF;
> +	err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[0]);
>  	mutex_unlock(&rv8803->flags_lock);
>  	if (err)
>  		return err;